2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Wireless Integrated Neural Interface Device for Chronic Neural Signal Recording

S. Kim, P. Tathiereddy, L. Rieth, R. Harrison, F. Solzbacher
University of Utah, US

wireless, neural interface, nearal

In this work, we present a fully assembled, wireless neural interface device consisting of a 100-channel microelectrode array and a custom-designed IC including a 100-channel amplifier, data processing, RF transmitter, and power and clock recovery for chronic neural signal recording. A few off-chip passive components such as power coil and SMD capacitors are necessary to complete the functional device. Applying high-density integration technologies to interconnect all sub components, the fully assembled wireless neural interface devices have been built. We developed a multi level assembly process using the Utah Electrode Array (UEA) as base plate: AuSn reflow flip chip bonding to connect the IC to the UEA and reflow soldering for SMDs and coil assembly. The biocompatible under bump metallization consists of a sputtered thin film sequence of Ti/Pt/Au with respective thicknesses of 100/200/150 nm. AuSn bumps were deposited on the Al pads of the IC chip, and the IC and UEA were connected during a reflow process. For protection of the flip chip bonds between the IC and UEA, a polymer underfiller (NAMICS U8433) was used. The Au power coil was connected to the IC using a metalized ceramic spacer and interconnections realized on the base plate of the UEA. SnCu0.7 solder paste was used to solder the SMDs and the spacer. All the interconnections between different components proved mechanical strength and stability.

Nanotech 2008 Conference Program Abstract